POLYMER TESTING
·
2021
·
IF 4.282
Tongtong Zhang,Jihuai Tan,Xue Han,Qinghe Fu,Muhua Chen,Yong Xu,Xinbao Zhu
Families of bio-based hyperbranched epoxy (HBPEEs) were successfully prepared using renewable xylitol, bisphenol A and epichlorohydrin as feedstocks. The structure and physical performances of HBPEEs were characterized by FTIR, NMR, GPC and viscosity evaluation. Then, they were used as high efficient tougheners for diglycidyl of bisphenol A/diethylenetriamine (DGEBA/DETA) networks. The results indicated that the incorporation of HBPEEs into the DGEBA system can significantly enhance the mechanical properties and solvent resistance properties of the hybrid (HBPEEs/DGEBA). In particular, toughened hybrids with 15 wt% HBPEE-2 exhibited the outstanding impact strength than that of neat DGEBA (37.4 kJ/m 2 vs. 11.8 kJ/m 2 ) due to its excellent compatibility of with DGEBA. Simultaneously, the ductile fracture morphology of the modified hybrids was also confirmed by SEM. In addition, the activation energies of HBPEE-2/DGEBA hybrids calculated from the non-isothermal curing kinetics were lower than that of neat DGEBA. All of the results suggested that the bio-based HBPEEs could be used as efficient tougheners applied in epoxy resins industry.
研究领域:
高分子化学
·
材料科学
·
绿色化学
·
复合材料
·
聚合物改性
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2015
·
IF 3.453
Xiaoyun Chen,Dong-Hau Kuo,Dongfang Lu,Yongxuan Hou,Yen-Rong Kuo
Mesoporous TiO 2 was synthesized by a hydrolysis precipitation method with the utilization of the biological renewable resource of lignin as template and TiCl 4 as reactant. The photocatalytic activity of TiO 2 was investigated by the degradation of phenol under UV light irradiation. The microstructure, crystallinity , powder characteristic, and chemical bonding of the catalyst were analyzed. The 500 °C-calcined TiO 2 had average crystallite size of about 11.1 nm and a mesoporous structure with specific area of 165.8 m 2 /g and pore volume of 0.312 cm 3 /g. The results showed that TiO 2 synthesized with lignin template exhibited high photocatalytic activity, which can be attributed to the electronegativity and the network skeleton of lignin to uniformly distribute the TiO 2 precursor for forming TiO 2 mesoporous particles. The mechanism for the improved photodegradation of the lignin-assisted TiO 2 was proposed.
研究领域:
材料科学
·
环境化学
·
纳米技术
·
光催化
·
绿色化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 35
·
IF 1.866
Yuanzhu Long,Fuhua Sun,Chao Liu,Dong Huang,Xingyi Xie
To explore a new blowing agent for polyurethanes (PUs), palmitic acid was grafted onto a branched polyethyleneimine (bPEI; weight-average molecular weight = 25,000 Da) via N,N ′-carbonyldiimidazole condensation to form a hydrophobically modified bPEI [palmitic acid grafted branched polyethyleneimine (C 16 –bPEI)] with a grafting rate of 12%. A CO 2 adduct of C 16 –bPEI, which trapped 16.8% CO 2 in it, was synthesized from C 16 –bPEI. The long alkyl chain grafting improved the dispersibility of the CO 2 adduct in the PU raw materials and favored a homogeneous release of CO 2 to blow PUs during the exothermic foaming process. The preliminary results show that the foams possessed a density of 72.0 kg/m 3 and a compressive strength of 246 kPa; this matched the required values of foams for the thermal insulation of underground steel pipes. This new blowing agent emitted nothing but CO 2 to the atmosphere, so it will not promote ozone depletion and will avoid global warming problems that are associated with traditional blowing agents such as chlorofluorocarbons and hydrochloroflourocarbons. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43874.
研究领域:
高分子化学
·
材料科学
·
绿色化学
·
能源与环境材料
·
工业催化
✓ 已验证
DOI
高影响因子
Journal of Nanomaterials
·
2019
·Vol. 2019
·期 1
·5290496
·
IF 2.233
Zhenzhu Yu,Fei Nan,Lu Su,Shaofei Zhang,Yan He
Intercalation and exfoliation are key steps in the preparation of graphene by thermal exfoliation, and they determine the quality of the final product. Therefore, it is important to explore the influence of intercalation agents on the intercalation and exfoliation of graphite. In this article, ammonium bicarbonate is intercalated into graphite with different degrees of oxidation to form a graphite intercalation compound (GIC) by means of ultrasound and stirring. Then, they are exfoliated by being heated at high temperatures. After ammonium bicarbonate intercalation and heating treatment, XRD, TG, and BET show that the intercalation and exfoliation effect of graphite oxide (GO) is better than that of graphite (G) and expanded graphite (EG). The intercalation mechanism is that the ammonia molecule in ammonium bicarbonate solution contains a wedge-shaped structure and active point, which provides empty orbits for graphite electrons and forms edge intercalation through physical interaction at the same time.
研究领域:
材料科学
·
纳米材料
·
物理化学
·
碳材料
·
功能材料
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·Vol. 9
·期 4
·105785
·
IF 5.909
Jinjia Guo,Yongmei Wang,Zhao Luo,Feng Zhang,Dewang Yang
Carbon cycle in coastal water is a significant dynamic component of global carbon budget , however, the diverse sources, carbon sinks and their complex interactions remained poorly understood. In order to detect the dissolved inorganic carbon (DIC) and their interactions, gas-liquid Raman spectroscopy was built and applied to simultaneously detect the constituents of air, dissolved CO 2 , HCO 3 - and chlorophyll in coastal water. The linear fitting curve between peak intensity and concentration was built for the quantitative analysis of HCO 3 - and CO 2 , meanwhile, the fluorescence peaks of chlorophyll at 679 nm were detected for the qualitative analysis. For the multi-components analysis, typical Raman spectra of the constituents of air, dissolved CO 2 , HCO 3 - in seawater, and the fluorescence spectra of chlorophyll in seawater were detected. Results showed that the time dependent change of CO 2 and O 2 in the air exhibited a contrary tendency, while that of dissolved CO 2 and O 2 was curved like a cosine. The changing tendency of relative concentrations of dissolved CO 2 was about 2 h earlier than CO 2 in air, due to the life activity of microorganisms driving the gas exchange at the air-sea interface. Furthermore, the study makes a study on the relationship between DIC and chlorophyll based on the detection of HCO 3 - and chlorophyll in coastal water, indicating that this gas-liquid Raman spectroscopy could successfully provide real-time analysis of multicomponent DIC in the air-sea exchanging process.
研究领域:
海洋化学
·
环境光谱学
·
碳循环
·
分析化学
·
生物地球化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Siwei Zhao,Ying Chen,Zhiyang Zhao,Longfei Jiang,Chi Zhang,Jianshou Kong,Xufei Zhu
Anodic TiO 2 nanotubes have been intensively studied for the application in supercapacitors , but the formation of nanograss is often avoided for the belief that it may retard capacitive performance. We fabricate TiO 2 nanotubes topped with nanograss by H 3 PO 4 solution soaking and hydrogenation doping, which in fact increases the capacitance of nanotubes in a fast and convenient way. The new structure exhibits an enhanced areal capacitance by up to 67.7% and by up to 23.5% after 2000 times of cycling. The capacitance generally increases with the nanotube length and reaches the maximum with an optimal nanograss length. The electric charge during hydrogenation doping is determined to quantify the general doping effect. Compared with ordinary nanotubes, nanograss has larger contact area with electrolyte during doping. Therefore, the grass-topped structure yields more electric charge and Ti 3+ during doping, which attributes to the improved capacitance.
研究领域:
材料科学
·
纳米技术
·
电化学
·
能源存储
·
表面工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Mengyi Wang,Li Yin,Mingqi Li,Shaohua Luo,Chao Wang
To develop low-cost, high-capacity and long-life anode materials for lithium-ion batteries, glucose-C and F-doped C coated SiO composites with adjustable pore structure (p-SiO@gl-C@F-doped C) are synthesized by facile and scalable methods. The combination of the heterogeneous dual-carbon shells and porous structure significantly promotes the reaction kinetics of the electrode, effectively suppresses and buffers the volume expansion of SiO, and largely enhances the stability of solid electrolyte interface of the electrode. In a half cell, the optimized p-SiO@gl-C@F-doped C (7:3) composite shows a stable discharge capacity of 785 mAh g −1 at a current density of 200 mA g −1 . The discharge capacity is maintained at 772 mAh g −1 after 200 cycles. At a current density of 400 mA g −1 , the electrode shows a discharge capacity of 633 mAh g −1 after 500 cycles, with a capacity degradation of ∼0.0096% per cycle from the 2nd cycle to the 500th cycle. The full cell which is composed of the commercial LiFePO 4 as a cathode and the optimized composite as an anode, exhibits high capacity and good cycling stability.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米复合材料
·
电池技术
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2015
·
IF 4.074
Chao Zhong,Chunming Wang,Fengxue Wang,Honghua Jia,Ping Wei,Yin Zhao
Cellulose isolation, a promising way for lignocellulosic biomass utilization, is always restricted by the poor solubility of cellulose. In this paper, tetra-n-methylammonium hydroxide (TMAH) was confirmed to be capable of readily dissolving/regenerating cellulose without chemical modification at room temperature. Meanwhile, cellulose isolation from lignocellulosic biomass by initially dissolving the biomass in TMAH followed by cellulose precipitation was proposed, and the isolated substance with average cellulose purity of 92.1 ± 0.3% could be obtained throughout this process under the optimum conditions: temperature 52 °C, time 60 min, and loading ratio of TMAH/biomass ( w / w ) 7.2:1. Besides, high efficiency cellulose isolation (i.e. >70% cellulose purity) could be continuously remained during 4-round cycles by using the recycled TMAH solvent without distinct activity loss.
研究领域:
生物质化学
·
绿色溶剂
·
天然高分子
·
可持续材料
·
生物精炼
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF FOOD PROPERTIES
·
2019
·
IF 1.398
Junsheng Li,Bixuan Wang,Junfu Fan,Xin Zhong,Guoxia Huang,Liujuan Yan,Xiane Ren
In this study, the effects of the disulfide bond cleavage induced by peracetic acid oxidation on the surface properties and surface hydrophobicity of soy proteins isolate (SPI) were investigated. The surface hydrophobicity, foaming capacity and emulsifying capacity of oxidized-SPI increased gradually at the initial stage with the increase of peracetic acid concentration. When the concentration of peracetic acid was increased up to 0.4%, compared with that of native SPI, the surface hydrophobicity, foaming capacity, emulsifying capacity and emulsifying stability of oxidized-SPI increased by 114.0, 81.4, 65.2, 49.8%, respectively, and achieved optimal results. However, excessive oxidation led to a decrease in surface hydrophobicity, foaming capacity and emulsifying stability of SPI, but it had no obvious effect on the foaming stability and emulsifying capacity of SPI. The foaming capacity, emulsifying capacity and emulsifying stability of SPI were positively related to the changes of surface hydrophobicity which caused by disulfide bond cleavage. The results of fluorescence spectroscopy, CD spectroscopy, and particle size analysis showed that the disulfide bond cleavage did cause great changes in the molecular structure of SPI, but there was no clear correlation between the molecular structural change and the surface activity of SPI. These suggested that the improvement of foaming capacity, emulsifying capacity and emulsifying stability of SPI could be achieved by changing its surface hydrophobicity via peracetic acid oxidation.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Mengxiao Zhong,Maoqiang Chi,Yun Zhu,Ce Wang,Xiaofeng Lu
Controllable fabrication of novel and uniform noble metal nanoparticles on a specific support with a superior catalytic or electrocatalytic performance is of significantly importance for practical applications. In this report, we demonstrated an effective way to fabricate uniform thin-walled Pd/polypyrrole (PPy) hollow nanotubes . The prepared Pd/PPy hybrid nanotubes exhibited an excellent peroxidase-like activity to oxidize a typical peroxidase substrate such as 3,3′,5,5′-tetramethylbenzidine in comparison with traditional Pd/C and Pd black catalysts. The outstanding catalytic activity of the Pd/PPy hybrid nanotubes for peroxidase mimicking could be resulting from their unique hollow characteristic and an interfacial effect between PPy and Pd components. Based on the favorable catalytic property of the Pd/PPy hybrid nanotubes, a convenient and rapid colorimetric way to sensitively determine ascorbic acid has been presented. The detection limit was around 0.062 μM and an excellent selectivity was also achieved. The developed detection system in this study could be extended to the fields of bioscience and biotechnology with promising prospects.
研究领域:
生物化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Weiguo Wang,Rongkai Du,Changzhi Dong,Jinwu Yan,Lei Zhang
A sensitive enzyme-linked immunosorbent assay (ELISA) has been developed based on the dual catalysis of dendritic Pd-Pt porous nanoparticles and horseradish peroxidase (HRP). The Pd-Pt porous nanoparticles, for the first time, were used to immobilize HRP. As a proof-of-concept demonstration, HRP functioned Pd-Pt porous nanoparticles were applied in hCG detection with a detection limit of 0.07 IU L −1 . The linear intervals is 0.1–6.4 IU L -1 . The Pd-Pt-HRP possesses a better sensitivity than the traditional BA-ELISA. Furthermore, the precision and reproducibility and selectivity were assessed to be eligible for the hCG monitoring.
研究领域:
生物化学
·
医学诊断
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 11
·14274-14285
·
IF 2.478
Gao Qianqian,Dai Yuqiang,Wei Xile,Zhou Changping,Gong Wenfeng,Song Haixiang,Guo Zhanhu,Li Chengbo
The Aurivillius compound Pb x Bi 6− x Fe 0.5 Co 0.5 Ti 4 O 18 thin films were prepared via chemical solution deposition method and the influence of Pb 2+ ions doping on the structure, ferroelectric and leakage properties were studied. With the increasing concentration of Pb 2+ ions, the lattice distortion is increased and the growth of the films along ab plane is promoted. The calculation results show that the internal stress of the films increases with the increase of Pb 2+ concentration. For the samples with low Pb 2+ doping concentration ( x < 0.6), the leakage current densities are also decreased, which can be attributed to the decrease in oxygen vacancy concentration. Due to the enhanced lattice distortion and decreased leakage current densities, the ferroelectric properties are improved. The film with x = 0.2 has a high saturation polarization of 42.3 µC/cm 2 . According to the fitting results, the leakage conduction mechanism is attributed to the combined effect of space-charge-limited conduction mechanism and ionic conduction mechanisms.
研究领域:
材料科学
·
凝聚态物理
·
功能材料
·
铁电学
·
薄膜制备
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）